Content is provided to you AS IS. You may access Content for your information and personal use solely as intended through the provided functionality of the Service and as permitted under these Terms of Service. You shall not download any Content unless you see a “download” or similar link displayed by YouTube on the Service for that Content.
–
phwd♦Jul 9 '10 at 14:58

8

You shall not copy, reproduce, distribute, transmit, broadcast, display, sell, license, or otherwise exploit any Content for any other purposes without the prior written consent of YouTube or the respective licensors of the Content. YouTube and its licensors reserve all rights not expressly granted in and to the Service and the Content.
–
phwd♦Jul 9 '10 at 14:58

Some videos (like the Vevo ones) get streamed; I haven't figured out how to save them yet.

But for the bulk of videos, they get saved to the computer's temporary folder until the video is navigated away from. On a Linux or Mac OS X computer, it's relatively easy to find and copy the temporary file elsewhere (renaming it to a .flv if it is a Flash video).

On Windows, the file's locked, so you need to use something like HoboCopy to copy it, which requires administrator rights and command-line usage. In places where you don't have administrator rights, like a computer lab, I launch a logging proxy (Fiddler2's lightweight and easy) to intercept all HTTP traffic, but this slows down all your browsing while it's capturing.

Usually, though, sites like KeepVid will work again later if you give them time.

A: Just open the page where the video or audio stream plays, and as
soon as it starts you will see a new
FlashGot Media status bar icon
flashing as a notification: you can
either left-click it to download all
the streams at once, or right-click to
choose among multiple streams, if more
than one have been found.
Alternatively, you can press ctrl+F7
or select the FlashGot Media command
from your context menu.

@PeterMortensen Well, looong time since your comment, and I don't know if youtube-dl worked at that time. However just for the record, seems to be working very well currently.
–
Ilari KajasteApr 30 '12 at 8:25

This service allows you convert a
Flash Video / FLV file (YouTube's
videos,etc) to MPEG4
(AVI/MOV/MP4/MP3/3GP) file online. It
is using a compressed domain
transcoder technology. It converts FLV to MPEG4
faster and less lossy than a typical
transcoder.

There are already a lot of answers but if the others don't meet your taste Freemake also has a free video downloader.

Freemake Video Downloader is a great, free Windows application which requires .NET platform to be installed on your system. It supports many video sites (says 40+ on the site), not just only YouTube. It also supports conversion to a large set of video formats.

I use JDownloader, but sometimes I also use http://savevideo.me because it lets you download the streamed file, it even lets you choose HD, or any resolution the video might had. The good news is that (as JDownloader) there's no conversion process involved, you get the real thing here.

It's actually pretty cool since this one besides being able to download and convert youtube videos can also work as a Youtube to mp3 ripper and convert youtube flv to mp3 files I can use on my pc or cell phone.